Shell and tube heat exchanger having zig-zag tubes



R. H. TULL SHELL AND TUBE HEAT EXCHANGER HAVING ZIG-ZAG TUBES F1196. la b 13. 1945 INVENTOR HoasR'r H. Tuu.

BY W I.

ATTORNEY Patented Aug lS, 1950 -SHELLAND TUBE HEAT EXCHANGEB HAVING ZIG-ZAG TUBES Robert H. Tull, Springfield, Mass., assignor, by mosne assignments, to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application March 13, 1945, Serial No. 582,507

My invention relates to a heat exchanger of the shell and tube type in which one fluid medium flows through tubes enclosed in a shell and another fluid medium flows through the shell in contact with the surfaces of the tubes.

One object of the invention is'to provide an improved heat exchanger of the type set forth.

; A further object of the invention is to devise a heat exchanger of the type set forth which will give a high rate of heat transfer from one medium to another without unduly prolonging the path of travel of the media or retarding the rate of flow thereoi'.

A still further object of the invention is to devise a heat exchanger for carrying out the foregoing objects which will be compact, light and inexpensive to produce.

A particular object is to provide a heat exchanger having a shell of minimum bulk, whereby the required space, weight and cost of the shell are reduced. l

These and other objects are effected by my invention as will be apparent from the following description and claims taken in connection 1th the accompanying drawings, forming a p t of this application, in which: l I

Fig. 1 is aview in longitudinal section of a heat exchangerembodying my invention, some of the tubes being omitted;

Fig. 2 is a section on line 11-11 of Fig. 1; and Fig. 3 is a section on line I1'I--II[ of Fig. 1. In the drawings there is shown a shell l pro- .vided with tube sheets i2 and I4 which, together with the respective adjacent end walls l6 and i6 of the shell form headers 2|) and 22 segregated flfrom the remainder of the interior of the shell.

4 Claims. (01. 252-238) ing from the left-hand end of the tubes in Fig. 1, diverging portions 34 and converging portions 36. The interior of the shell, between the tube sheets i2- and i4, is provided with baiiies 40 and 42. The baflles 40 and 42 cooperate with each other and with the tube sheets I2 and I 4 to provide compartments 46, 48, 50 and 52. The baflles 40 extend inwardly from the wall of the shell and are provided with central openings 54, while, the bailles 42 have their peripheries spaced from the wall of the shell so as to form openings 56.

. As will be seen from Fig. 1, the tube portions 34,

charge header 22 and an outlet 32 located adjacent the inlet header 26. A fluid mediumadmitted through the inlet 30'" and discharged through the outlet 32 will be in counterflow relation with the medium flowing through the tubes 24.

In order to carry out the invention, the tubes 24 are alternately bent towards the wall and the longitudinal axis of the shell, so as to form, startat the point of maximum divergence, pass through, and are preferably supported by the batfles 40. The tube portions 36, at the point of maximum convergence, pass through the bames 42, of which only one is shown in the illustrated embodiment. The baffles 42 may be secured to the wall of the shell, by a spider or the like, not shown, so as to act as a support for the tube portions passing therethrough, or the baiiies 42 may be carried by said tube portions.

By this arrangement, a fluid medium, entering the space 46, flowing through the shell, and emerging through the outlet 32, will always flow at an angle to the longitudinal axes of the tubes and substantially parallel to the planes of the flns on the tubes.

Operation ,A medium, such as warm liquid refrigerant, is admitted through the inlet tube 26, flows through the tubes 24 and is discharged through the outlet 28. Another medium, such as relatively cool vaporized refrigerant, is admitted through the inlet 36 into the space 46 and into contact with the diverging tube portions 34 in this space. The gas passes between the fins of the tubes and between and around the tubes themselves, and flows through the central opening 54 into the next space 48 where the gas comes into contact with the converging portions 36 of the tubes. From the space 48, the gas flows through the openings 56 into the space 50 and from the space 50 through the opening 54 into the space 52 and out through the outlet 32. The path of flow of the gas through the tubes 24 and from the inlet 30 to the outlet 32 is indicated by the arrows in Fig. 1.

It will thus be seen that by this arrangement of thetubes and baflles a gas flowing through the interior of the shell must, cross and recross the converging and diverging tube portions at an angle to the axisof the tube portions and substantially parallel to the planes of the flns. By

,this means the gas will have intimate and pro- I tubes inwardly at the baflie 42 to provide the passage space 56 for flow of fluid, the shell need be only big enough to enclose the baflles 49, thereby reducing the required space, weight and cost of the shell.

The structure described is adapted for use wherever it is desired to bring two fluid media having a temperature diil'erential into heat exchange relation.

While- I have shown my invention in but one form, it will be obvious to those skil ed in the art that it is not so limited, but is susceptible of various chan es and modifications without departing from the spirit thereof.

What I claim is: 1. A heat exchanger comprising an elongated shelLan intake header at one end of said shell,

a discharge header at the other end of said shell. a plurality of tubes extending longitudinally through said shell and'communicating at their opposite ends with said headers, said tubes providing a flow path for a fluid medium and being bent, successively, toward the wall of said shell and toward the center of said shell, to provide alternately diverging and converging portions, there being an inlet disposed near one end of said shell and leading to the interior of the shell between said headers and an outlet disposed near the other end of said shell and leading from said interior of said shell, whereby the interior of said shell between said headers provides a flow path for another fluid medium, a baflie extending inwardly from the wall of said shell and through which said diverging tubes pass near their point of'maximum divergence, there being a central opening in said baflle, and a bailie having its periphery spaced from the wall'of said shell and through which said converging tubes pass near their point of maximum convergence. said bames being so arranged within the shell that a fluid medium flowing through said interior of said shell is compe led to flow through the central opening being of uniform cross section between the headers, a nest of tubes extending longitudinally through the shell and communicating at their opposite ends with the headers, the tubes providing a flow path for one fluid and being of zigzag form, there being an inlet disposed near one end of the shell and leading to the interior of the shell between the headers and an outlet disposed near the other end of the shell and leading from the interior of the shell, whereby the interior of the shell between the headers provides I attheinflectionorbendzonesbetweenthe headers 4 a flow path for a second fluid, and bailes located ing. from the inlet to the outlet whereby such fluid is constrained to flow to and fro across tubes oi. the nest.

3. A heat exchanger comprising an elongated shell, an intake header at one end and a discharge header at the other end of the shell, a hostel tubes extending longitudinally through the shell and communicating at their opposite ends with the headers, the tubes providing a flow path for one fluid and being of zigza form, there being an inlet disposed near one end of the shell and leading to the interior of the shell between the headers and an outlet disposed near the other end of the shell and leading from the interior of the shell, whereby the interior of the shell between the headers provides a flow path for a second fluid, and baiiles located at the inflection or ben 'zones between the headersand having charge header at the other end of the shell, a

nest of tubes extending longitudinally through the shell and communicating at their opposite ends with the headers, the tubes providing a flow path forone fluid and being of zigzag form with contiguous convergent and divergent sections, there being an inlet disposed near one end of the shell and leading to the interior of the shell between the headers and an outlet disposed near the other end of the shell and leading from the interior of the shell, whereby the interior of the shell between the headers provides a flowpath for a second fluid, and transversely extending baflles spaced axially of said tubes dividing the interior space of the shell into a plurality of passes, said baflies being mounted at the points of maximum convergence and maximum divergence of the tubes with the perimeter of a baflle located at a point of maximum convergence spaced from the interior wall of the shell to provide a passage for flow of said second fluid between contiguous passes while a baflle at the point of maximum divergence has its perimeter in contact with the wall of the shell and is formed with a central opening for'said flow.

ROBERT H. TULL.

REFERENCES crrEn The following references are of record in the flle of this patent:

' UNITED STATES PA'I'ENTS Number Name Date 898,932 Schnug Sept. 15, 1908 N FOREIGN PATENTS Number Country Date 22,097 Great Britain Sept. 28, 1912 402,628 Great Britain Dec. '1, 1933 July 19, 1934 413,406 Great Britain 

